What Causes Water Leak Under Sink
Under-sink leaks originate from supply line connections, the faucet base, the P-trap assembly, the garbage disposal connection, the dishwasher drain hose, or the drain tailpiece. Supply leaks are pressurized and constant; drain leaks only occur when the sink is in use.
Boise-specific factor: Hard water deposits weaken supply line connections over time. Braided stainless steel supply lines are recommended replacements — older plastic or chrome supply lines in many Boise homes are prone to sudden failure. Garbage disposal drain connections are another common leak point in Boise kitchens.
Signs You Have Water Leak Under Sink
Watch for these warning signs in your home:
- ✓ Water pooling in the cabinet under the sink
- ✓ Dampness or water stains on the cabinet floor
- ✓ Musty or mold smell from under the sink
- ✓ Warped or discolored cabinet bottom
- ✓ Dripping visible when looking under the sink with a flashlight
Can You Fix This Yourself?
Place a flashlight under the sink, run the water, and watch for drips. Tighten supply line connections gently. Check the P-trap connections — hand-tight should be sufficient. If the leak is from the faucet base, the faucet's O-rings or cartridge need replacement.
If the problem persists or you're unsure, call a licensed plumber. Attempting complex repairs without proper tools can cause further damage and void warranties.
How Our Plumbers Fix Water Leak Under Sink
We locate the exact leak source, replace supply lines with braided stainless steel, re-seal or replace P-trap components, and check for hidden water damage to cabinets and flooring beneath. Supply line replacement is a preventive measure we recommend during any under-sink repair.
Experiencing water leak under sink? Call now for same-day diagnosis.
Call (208) 555-0199 — Free EstimateWater Leak Under Sink Repair Cost in Boise
Typical cost to fix water leak under sink in the Boise area: $75-$200 for connection repair, $150-$400 for faucet repair/replacement. We provide an upfront quote before starting any work — no surprises.
How to Prevent Water Leak Under Sink
Replace rubber or plastic supply lines with braided stainless steel. Inspect under-sink connections every 6 months. Don't overtighten plastic P-trap fittings.
Frequently Asked Questions
Why is my kitchen sink leaking underneath?
The most common sources: loose P-trap connections (drain leak — only when water runs), worn supply line fittings (constant drip), garbage disposal gasket failure, or dishwasher drain hose. A flashlight inspection while running water quickly identifies the source.
How much does it cost to fix a leak under the sink?
Most under-sink leaks are fixed for $75-$200 — tightening connections, replacing washers, or installing new supply lines. If the faucet itself is leaking, repair or replacement costs $150-$400.
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